• 제목/요약/키워드: three fold helix

검색결과 5건 처리시간 0.016초

3회나선축을 갖는 Na-cellulose II의 형성조건에 관한 고찰 (Formation Conditions of Na-cellulose II with Three Fold Helix)

  • 김남훈;이명구
    • Journal of the Korean Wood Science and Technology
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    • 제27권1호
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    • pp.18-23
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    • 1999
  • 3회축을 갖는 Na-cellulose II의 형성조건을 X선회절법을 이용하여 검토하였다. 그 결과 Na-cellulose II는 Na-cellulose I 을 거쳐서 형성되며 결정중의 알칼리농도가 Na-cellulose I 이나 III보다 높은 조건에서 형성되는 것으로 생각되었다. 2회축에서 3회축으로의 섬유주기의 급격한 변화는 알칼리 처리 후의 수분제거방법에 의해 크게 영향받는 것으로 생각되었다. 동(銅)-알칼리셀룰로오스 복합체의 결정은 팽윤상태에서 안정된 구조를 가지며 건조에 의해 결정구조가 변화되었다.

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Digital Technology Practices and Vaccine Campaign in Korea: International Perceptions on Health Diplomacy amid COVID-19 Crisis

  • Tahira, Iffat
    • Journal of Contemporary Eastern Asia
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    • 제21권2호
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    • pp.27-46
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    • 2022
  • The purpose of this study is two-fold: first, to discuss the concept of health diplomacy and the Korean government's response to contain the COVID-19 pandemic; second, to assess and compare assumptions of variances about foreigners' perceptions of how Korea is leveraging digital technology in battling the coronavirus spread, and its vaccine campaign; through the lenses of Chinese, Filipino, and Pakistani foreign nationals who are currently living in Korea. A total of 219 foreigners responded to the survey. The collected data were analyzed as percentages, mean averages, t-test, and ANOVA for statistical analysis. Results show that Korea is utilizing its digital technology practices and vaccine campaign in battling the pandemic through efforts of health diplomacy. ANOVA indicated significant results and assumptions of variance across three ethnic groups showing the Pakistani population had higher mean scores than the Chinese and Filipino about Korea's health diplomacy during the pandemic. This study contributes to the literature on Korea's digital technology practices and vaccine campaigns amidst the COVID-19 pandemic by promoting its image through health diplomacy efforts. It projects the country's soft image on a global scale, to save the lives of locals and foreign nationals, by providing insights into health diplomacy in Korea.

Structural basis of novel TRP14, thioredoxin-related protein that regulates TNE-$\alpha$ signaling pathways

  • Woo, Joo-Rang;Jeong, Woo-Jin;Rhee, Sue-Goo;Ryu, Seong-Eon
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2003년도 춘계학술연구발표회
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    • pp.18-18
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    • 2003
  • Thioredoxin (Trx) is a small redox protein that is ubiquitously distributed from achaes to human. In diverse organisms, the protein is involved in various physiological roles by acting as electron donor and regulators of transcription and apoptosis as well as antioxidants. Sequences of Trx within various species are 27~69% identical to that of E. coli and all Trx proteins have the same overall fold, which consists of central five β strands surrounded by four α helices. The N-terminal cysteine in WCGPC motif of Trx is redox sensitive and the motif is highly conserved. Compared with general cysteine, the N-terminal cysteine has low pKa value. The result leads to increased reduction activity of protein. Recently, novel thio.edoxin-related protein (TRP14) was found from rat brain. TRP14 acts as disulfide reductase like Trx1, and its redox potential and pKa are similar to those of Trx1. However, TRP14 takes up electrons from cytosolic thioredoxin reductase (TrxR1), not from the mitochondrial thioredoxin reductase (TrxR2). Biological roles of TES14 were reported to be involved in regulating TNF-α induced signaling pathways in different manner with Trx1. In depletion experiments, depletion of TRP14 increased TNF-α induced phosphorylation and degradation of IκBα more than the depletion Trx1 did. It also facilitated activation of JNK and p38 MAP kinase induced by TNF-α. Unlike Trx1, TRP14 shows neither interaction nor interference with ASK1. Here, we determined three-dimensional crystal structure of TRP14 by MAD method at 1.8Å. The structure reveals that the conserved cis-Pro (Pro90) and active site-W-C-X-X-C motif, which may be involved in substrate recognition similar to Trx1 , are located at the beginning position of strand β4 and helix α2, respectively. The TRP14 structure also shows that surface of TRP14 in the vicinity of the active site, which is surrounded by an extended flexible loop and an additional short a helix, is different from that of Trx1. In addition, the structure exhibits that TRP14 interact with a distinct target proteins compared with Trx1 and the binding may depend mainly on hydrophobic and charge interactions. Consequently, the structure supports biological data that the TRP14 is involved in regulating TNF-α induced signaling pathways in different manner with Trx1.

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The Role of Residues 103, 104, and 278 in the Activity of SMG1 Lipase from Malassezia globosa: A Site-Directed Mutagenesis Study

  • Lan, Dongming;Wang, Qian;Popowicz, Grzegorz Maria;Yang, Bo;Tang, Qingyun;Wang, Yonghua
    • Journal of Microbiology and Biotechnology
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    • 제25권11호
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    • pp.1827-1834
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    • 2015
  • The SMG1 lipase from Malassezia globosa is a newly found mono- and diacylglycerol (DAG) lipase that has a unique lid in the loop conformation that differs from the common alpha-helix lid. In the present study, we characterized the contribution of three residues, L103 and F104 in the lid and F278 in the rim of the binding site groove, on the function of SMG1 lipase. Site-directed mutagenesis was conducted at these sites, and each of the mutants was expressed in the yeast Pichia pastoris, purified, and characterized for their activity toward DAG and p-nitrophenol (pNP) ester. Compared with wild-type SMG1, F278A retained approximately 78% of its activity toward DAG, but only 11% activity toward pNP octanoate (pNP-C8). L103G increased its activity on pNP-C8 by approximately 2-fold, whereas F104G showed an approximate 40% decrease in pNP-C8 activity, and they both showed decreased activity on the DAG emulsion. The deletion of 103-104 retained approximately 30% of its activity toward the DAG emulsion, with an almost complete loss of pNP-C8 activity. The deletion of 103-104 showed a weaker penetration ability to a soybean phosphocholine monolayer than wild-type SMG1. Based on the modulation of the specificity and activity observed, a pNP-C8 binding model for the ester (pNP-C8, N102, and F278 form a flexible bridge) and a specific lipid-anchoring mechanism for DAG (L103 and F104 serve as "anchors" to the lipid interface) were proposed.

쌍별귀뚜라미(Gryllus bimaculatus)의 l(2)efl cDNA 클로닝과 발현분석 (Lethal (2) Essential for Life [l(2)efl] Gene in the Two-spotted Cricket, Gryllus bimaculatus (Orthoptera: Gryllidae))

  • 권기상;이누리;권오유
    • 생명과학회지
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    • 제31권7호
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    • pp.671-676
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    • 2021
  • 쌍별 귀뚜라미(Gryllus bimaculatus)에서 lethal (2) essential for life [l(2)efl]을 코드한 cDNA를 분리하여 GBl(2)efl이라 하였다. GBl(2)efl는 N-glycosylation 한곳과 phosphorylation site를 15곳 가진 189 aa로 구성되며6.2등전점과 21.19 kDa 분자량을 가진다. GBl(2)efl 단백질의 이차구조는 random coils (56.08%), alpha-helix (22.22%), extended strands (17.99%), beta turns (3.7%)로 이루어진다. GBl(2)efl 는 지금까지 보고된 l(2)efl들과는48-69%의 상동성을 보인다. GBl(2)efl은1일, 3일 starvation일때에 각각 dorsal longitudinal flight muscle과 Malpighian tubules에서 mRNA발현이 증가하였다. 한편, ER stress 조건에서는GBl(2)efl 발현은 fat body에서 증가하였다. 본 연구는 곤충의 생존에 기여하는 생리학적 메커니즘을 이해와 효과적인 해충 관리 통제를 수행할 수 있는 능력을 향상에 많은 힌트를 줄 수 있는 실마리를 제공할 수 있을 것이다.